Detect image properties in a local file

Perform image properties detection on a local file.

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For detailed documentation that includes this code sample, see the following:

Code sample

Go

Before trying this sample, follow the Go setup instructions in the Vision quickstart using client libraries. For more information, see the Vision Go API reference documentation.

To authenticate to Vision, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 


// detectProperties gets image properties from the Vision API for an image at the given file path.
func detectProperties(w io.Writer, file string) error {
	ctx := context.Background()

	client, err := vision.NewImageAnnotatorClient(ctx)
	if err != nil {
		return err
	}

	f, err := os.Open(file)
	if err != nil {
		return err
	}
	defer f.Close()

	image, err := vision.NewImageFromReader(f)
	if err != nil {
		return err
	}
	props, err := client.DetectImageProperties(ctx, image, nil)
	if err != nil {
		return err
	}

	fmt.Fprintln(w, "Dominant colors:")
	for _, quantized := range props.DominantColors.Colors {
		color := quantized.Color
		r := int(color.Red) & 0xff
		g := int(color.Green) & 0xff
		b := int(color.Blue) & 0xff
		fmt.Fprintf(w, "%2.1f%% - #%02x%02x%02x\n", quantized.PixelFraction*100, r, g, b)
	}

	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the Vision quickstart using client libraries. For more information, see the Vision Java API reference documentation.

To authenticate to Vision, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 


import com.google.cloud.vision.v1.AnnotateImageRequest;
import com.google.cloud.vision.v1.AnnotateImageResponse;
import com.google.cloud.vision.v1.BatchAnnotateImagesResponse;
import com.google.cloud.vision.v1.ColorInfo;
import com.google.cloud.vision.v1.DominantColorsAnnotation;
import com.google.cloud.vision.v1.Feature;
import com.google.cloud.vision.v1.Image;
import com.google.cloud.vision.v1.ImageAnnotatorClient;
import com.google.protobuf.ByteString;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class DetectProperties {
  public static void detectProperties() throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String filePath = "path/to/your/image/file.jpg";
    detectProperties(filePath);
  }

  // Detects image properties such as color frequency from the specified local image.
  public static void detectProperties(String filePath) throws IOException {
    List<AnnotateImageRequest> requests = new ArrayList<>();

    ByteString imgBytes = ByteString.readFrom(new FileInputStream(filePath));

    Image img = Image.newBuilder().setContent(imgBytes).build();
    Feature feat = Feature.newBuilder().setType(Feature.Type.IMAGE_PROPERTIES).build();
    AnnotateImageRequest request =
        AnnotateImageRequest.newBuilder().addFeatures(feat).setImage(img).build();
    requests.add(request);

    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (ImageAnnotatorClient client = ImageAnnotatorClient.create()) {
      BatchAnnotateImagesResponse response = client.batchAnnotateImages(requests);
      List<AnnotateImageResponse> responses = response.getResponsesList();

      for (AnnotateImageResponse res : responses) {
        if (res.hasError()) {
          System.out.format("Error: %s%n", res.getError().getMessage());
          return;
        }

        // For full list of available annotations, see http://g.co/cloud/vision/docs
        DominantColorsAnnotation colors = res.getImagePropertiesAnnotation().getDominantColors();
        for (ColorInfo color : colors.getColorsList()) {
          System.out.format(
              "fraction: %f%nr: %f, g: %f, b: %f%n",
              color.getPixelFraction(),
              color.getColor().getRed(),
              color.getColor().getGreen(),
              color.getColor().getBlue());
        }
      }
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Vision quickstart using client libraries. For more information, see the Vision Node.js API reference documentation.

To authenticate to Vision, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

const vision = require('@google-cloud/vision');

// Creates a client
const client = new vision.ImageAnnotatorClient();

/**
 * TODO(developer): Uncomment the following line before running the sample.
 */
// const fileName = 'Local image file, e.g. /path/to/image.png';

// Performs property detection on the local file
const [result] = await client.imageProperties(fileName);
const colors = result.imagePropertiesAnnotation.dominantColors.colors;
colors.forEach(color => console.log(color));

PHP

Before trying this sample, follow the PHP setup instructions in the Vision quickstart using client libraries. For more information, see the Vision PHP API reference documentation.

To authenticate to Vision, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

namespace Google\Cloud\Samples\Vision;

use Google\Cloud\Vision\V1\ImageAnnotatorClient;

/**
 * @param string $path Path to the image, e.g. "path/to/your/image.jpg"
 */
function detect_image_property(string $path)
{
    $imageAnnotator = new ImageAnnotatorClient();

    # annotate the image
    $image = file_get_contents($path);
    $response = $imageAnnotator->imagePropertiesDetection($image);
    $props = $response->getImagePropertiesAnnotation();

    print('Properties:' . PHP_EOL);
    foreach ($props->getDominantColors()->getColors() as $colorInfo) {
        printf('Fraction: %s' . PHP_EOL, $colorInfo->getPixelFraction());
        $color = $colorInfo->getColor();
        printf('Red: %s' . PHP_EOL, $color->getRed());
        printf('Green: %s' . PHP_EOL, $color->getGreen());
        printf('Blue: %s' . PHP_EOL, $color->getBlue());
        print(PHP_EOL);
    }

    $imageAnnotator->close();
}

Python

Before trying this sample, follow the Python setup instructions in the Vision quickstart using client libraries. For more information, see the Vision Python API reference documentation.

To authenticate to Vision, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

def detect_properties(path):
    """Detects image properties in the file."""
    from google.cloud import vision

    client = vision.ImageAnnotatorClient()

    with open(path, "rb") as image_file:
        content = image_file.read()

    image = vision.Image(content=content)

    response = client.image_properties(image=image)
    props = response.image_properties_annotation
    print("Properties:")

    for color in props.dominant_colors.colors:
        print(f"fraction: {color.pixel_fraction}")
        print(f"\tr: {color.color.red}")
        print(f"\tg: {color.color.green}")
        print(f"\tb: {color.color.blue}")
        print(f"\ta: {color.color.alpha}")

    if response.error.message:
        raise Exception(
            "{}\nFor more info on error messages, check: "
            "https://cloud.google.com/apis/design/errors".format(response.error.message)
        )

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